Siege of Kameyama

The Siege of Kameyama was a failed attempt by the Tokugawa Shogunate loyalists to capture the city of Kameyama from the pro-Emperor army of Mori Tadanaga, who had rebelled against the Tsu Domain and the Shogun. In the battle the Tokugawa lost invaluable general Mashashi Nakayama to a Paixhans exploding shell.

Background
General Mashashi Nakayama and an army of 15,000 Tsu Domain troops loyal to the Tokugawa Shogunate were the last troops in between the Kyotan rebels and the city of Tsu, the capital of the Tsu Domain loyalists to the Shogunate after the main force in Kyoto joined the Imperial Army. Mori Tadanaga, the commander of the rebels, captured Kameyama without a fight, with aid from the Royal Navy. Masashi set out to retake the city, despite being outnumbered. He had a few artillery pieces with him, so he could bombard the city walls before he launched an attack. However, Mori Tadanaga was also equipped with artillery pieces leased by Britain, and was supplied with vintage American Civil War rifles.

Siege
The Shogunate army settled down for a siege, with occasional artillery duels. The British Royal Navy withdrew from the waters after a shell from the Shogun's army entered the engine room of steamer HMS Exorcist, and the city was left to fend for itself. However, taking advantage of Paixhans explosive shells, the city inflicted heavy damage on the besieging army. One shell killed Mashashi, and his demoralized troops decided to withdraw. The garrison of the city pursued but were also dealt heavy losses in a rearguard action. In the end, the Shogunate lost not only the army and general, but the support of the Tsu, who defected soon after.